The present invention relates to an anhydrous alcohol fuel gel composition which does not liquify during burning, but maintains its free-standing original shape such as a cube and the like. This anhydrous fuel gel does not flow during the burning period but remains in place, does not spread and will not penetrate the charcoal or wood being ignited, which is critical to fire starters.
Liquid fuels, or solids that liquify while burning, may flow through seams or openings in the floor of a brazier, creating a fire hazard. In a fireplace, such liquifaction could saturate the floor surface, and in a wood-burning stove, be a possible fire hazard, also.
A wide variety of products are currently sold for use as charcoal and wood fire starters. However, many of these products are subject to one or more disadvantages. For example, liquid type fuels tend to burn very rapidly and require another application for ignition. This shortcoming of liquid fuels is due to their liquid form which does not normally adhere in sufficient amounts to the briquettes but instead flows off the sides thereof. Additionally, liquid fuels can be dangerous because of the problem of flame flashback wherein the dispensing stream of liquid becomes ignited causing the liquid in the dispensing container to ignite.
Another commercial fire starter product is an impregnated solid which requires a physical breaking and distribution thereof. Such steps are time consuming, and often result in the soiling of the hands or clothes of the user, thereby causing consumer dissatisfaction.
Gel hydrocarbon based fire starter products as shown in U.S. Pat. Nos. 718,318 and 1,868,568, have also been used, but these are characterized by burning with an odor and producing a relatively large amount of soot. Additionally, these gel products tend to melt upon burning and do not maintain their shape but instead tend to flow over the charcoal briquettes forming a thin film of gelled material analagous to the liquid fuels. This characteristic shortens the product burning time and relatively large amounts of the gel must be used to effect ignition of the charcoal.
Alcohol fuel gel products are known for commercial applications and such products burn with a clean, non-sooty flame. Such products are available in containers wherein the burning occurs, as shown in U.S. Pat. Nos. 1,266,080; 1,277,149; 1,389,638; and 1,484,190. The containment of the alcohol gel eliminates the necessity of producing a non-liquifying immobile gel which retains its original shape during burning. The alcohol fuel gel may also be in the form of a paste gel which is dispensed from a squeeze tube as shown in U.S. Pat. No. 3,183,068; or in the form of individual cubes as disclosed in U.S. Pat. No. 1,545,595. All of aforesaid alcohol fuel gels comprise a lower aliphatic alcohol such as ethyl and methyl alcohol per se or in admixture and the sodium stearate gelling agent made in situ in the presence of water, either by reacting aqueous sodium hydroxide with stearic acid dissolved in alcohol, or by reacting caustic soda dissolved in non-anhydrous alcohol (i.e. 190 proof denatured alcohol). U.S. Pat. No. 1,545,595 utilizes a considerable amount of a non-solvent for the fatty acid soap reaction product, such as methyl acetone, in order to prevent liquifaction of the alcohol gel while burning. Water is present to help solution of the soap (sodium stearate), the presence of a minimal amount (5-25%) of water being necessary to develop a good gel structure as alleged in U.S. Pat. No. 3,183,008.
Alcoholic fuel gels have also been made with non-soap gelling agents including natural and synthetic gums such as cellulose and modified celluloses, i.e. methyl or ethyl cellulose, hydroxyethyl-, hydroxymethyl-cellulose, nitrocellulose and the like; and hydrophilic carboxy vinyl polymers. U.S. Pat. No. 3,183,068 discloses that water must be present in the alcohol gel composition consisting of a mixture of ethanol and methanol in the weight ratio of 7:1, in order to develop a good gel structure which does not lose its shape as extruded, or run off during combustion. U.S. Pat. No. 3,148,958 also discloses an extrudable stable gel which does not break down during combustion, comprising a mixture of ethanol and isopropyl alcohol (2.5:1 weight ratio) or ethanol per se, a carboxyvinyl copolymer gelling agent and about 5-10% water. The alcohol fuel gel in U.S. Pat. No. 3,214,252 comprises an olefinmaleic anhydride copolymer gelling agent, methyl-, ethyl- or propyl-alcohol, up to 40% water and alkaline neutralizing compound to adjust the pH of the composition to about 6-9, which is extrudable and retains its shape during the period of combustion. Above a pH of 9, said gel is fluid, could not be extruded from the tube and did not hold its shape although capable of burning. U.S. Pat. No. 3,271,120 discloses a stable audibly burning alochol gel comprising about 65-80% ethanol or a mixture of ethanol and methanol, nitrocellulose gelling agent and 15-30% water which gells the mixture. The thusly formed gel retains its shape throughout the combustion period. U.S. Pat. No. 4,084,939 discloses ethylene-acrylic acid copolymer dispersions as gelling agent, 40-90% of an alcohol containing 1-6 carbon atoms or mixtures thereof (ethanol and isopropanol in weight ratio of 2:1) and encapsulated volatile solvent (xylene) which crackles as it burns. U.S. Pat. No. 4,261,700 discloses a shape-retaining mass of fuel gel composition containing 60-90% of an alcoholic mixture of a major amount of ethanol and a minor amount of C.sub.3 -C.sub.4 alcohol, and a neutralized carboxy-vinyl polymer gelling agent, 3.5-11% water and 5-30% propellant in a pressurized container.
Thus, it is apparent that the above cited prior art alcohol fuel gels, regardless of the particular gelling agent utilized or the particular lower aliphatic alcohol or combination of alcohols used, require the presence of some water to provide a desired gel structure. In addition, the soap gelling agent needs water to act as a solution aid for said soap.
U.S. Pat. No. 3,754,877 discloses a gelled fuel composition which does not require water to promote gelation, comprising an aliphatic alcohol having 1-5 carbon atoms and 0.2-2% of a cross-linked olefin-modified hydroxyalkyl cellulose. The resultant gels are stiff, rubbery and non-flowable gels, which burn smoothly with a colorless soot-free flame, leaving little residue after burning. These gels have particular utility as fuels for chafing dishes and warming trays. No mention is made of its use as a fire starter.
U.S. Pat. No. 4,238,201 discloses a grill charcoal lighter comprising a pasty emulsion in a cellophane foil, comprising 65-94% alcohol such as isopropanol, 4-13% of a triethanolamine salt of alkylbenzene sulfonic acid in an aqueous solution as emulsifier, and 2-22% of fine particles of silicon tetrachloride as filler.
However, none of the above cited art discloses a solid alcohol fuel for starting charcoal or wood fires comprising an anhydrous gel which does not liquify during combustion, comprising a major proportion of an anhydrous alcoholic mixture of methanol and isopropanol in the weight ratio of about 3:1, and a fatty acid soap gelling agent prepared in situ.